July 1, 1865.] THE TECHNOLOGIST. 



THE TELEGRAPH. 535 



realise it, in other words to telegraph, however slowly and restrictedly, 

 requires three agents : — 1. A message-sender. 2. A message-carrier. 

 3. A message-receiver. 



All are of equal importance, but the second is of greatest interest, 

 inasmuch as it is the most variable of the three, and one which has 

 been most largely changed in the progress of time, since men first 

 systematically telegraphed to each other. A sure, swift messenger, able 

 to carry on each journey a reasonable burden of messages, is plainly the 

 great desideratum. The medium, the cipher, or symbol in which the 

 information to be sent, shall be imbedded by the sender, and from which 

 it shall be liberated or interpreted by the receiver, is as plainly of far 

 less moment. There is in truth but this restriction, that the latter shall 

 witness a visible or audible signal, something that speaks to the eye or 

 speaks to the ear. No doubt signals addressed to the organ of touch 

 might be used, as in truth they are sometimes employed, but their 

 application is very limited, compared with that of a sight or a sound. 



Accordingly, in all ages and countries, men have addressed their 

 telegraphic signals to the eye, or the ear, or to both. Two important 

 professions specially employ one of these organs. The sailor, famous 

 for his long-sight, deals preeminently in visible signals. The soldier, 

 whose ear never sleeps, deals in audible ones. The flag is the symbol of 

 the one. The bugle or drum the other. 



It would be very instructive, had we time for the enquiry, to notice 

 how essentia] to the art of navigation is an elaborate system of telegra- 

 phy. From the moment he sets sail from one port, till he furls his 

 canvass in another, the sailor is constantly looking out for, and receiving 

 telegrams. Church-steeples and towering cliffs, floating buoys, and har- 

 bour-lights beckon him forth, and guide him out to sea. In mid-ocean 

 his eye is constantly scanning the horizon, watching for sister ship, or 

 floating wreck, or the surf breaking on a rock unmapped in his chart. 

 The barometer is for him a telegraphic dial, telling by its fall, of the 

 far distant storm which is signalling thereby its rapid approach. The 

 thermometer is a telegraphic dial, telling by its fall, of the unwelcome 

 neighbourhood of the invisible iceberg. The plummet is a telegraphic 

 dial, telling by its shortened line that land is ahead. At midday the 

 sun telegraphs to him his place on the earth's surface. At midnight 

 the north star warns him if his compass needle is wrong, and all the 

 planets help him in his course. If he is sailing in unknown seas, the 

 wind brings him as it did to Milton's voyagers the smell of spices from 

 some Araby the Blest, or the waves carry, as they did to Columbus, a 

 fruit-bearing branch to his vessel ; or a singing bird alights on his 

 shrouds, and repeats the story of Noah's dove, and though the dialect is 

 strange, every sailor knows that the song is of the hidden woods ; or a 

 carved stick drifts by, [and the pilot can tell that to windward there is 

 an invisible land with fruit-bearing trees, and melodious birds, and 

 strange industrial men. When he passes a sister ship, he silently 

 VOL. vi. 3 L 



